From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Fastabend Subject: [bpf-next PATCH 2/3] bpf: libbpf support for msg_push_data Date: Thu, 18 Oct 2018 14:52:08 -0700 Message-ID: <20181018215208.22362.10984.stgit@john-Precision-Tower-5810> References: <20181018215041.22362.36585.stgit@john-Precision-Tower-5810> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, john.fastabend@gmail.com To: ast@kernel.org, daniel@iogearbox.net Return-path: Received: from [184.63.162.180] ([184.63.162.180]:57070 "EHLO john-Precision-Tower-5810" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725751AbeJSFzK (ORCPT ); Fri, 19 Oct 2018 01:55:10 -0400 In-Reply-To: <20181018215041.22362.36585.stgit@john-Precision-Tower-5810> Sender: netdev-owner@vger.kernel.org List-ID: Add support for new bpf_msg_push_data in libbpf. Signed-off-by: John Fastabend --- tools/include/uapi/linux/bpf.h | 20 +++++++++++++++++++- tools/testing/selftests/bpf/bpf_helpers.h | 2 ++ 2 files changed, 21 insertions(+), 1 deletion(-) diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 5e46f67..1e9fbc5 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -2215,6 +2215,23 @@ struct bpf_stack_build_id { * pointer that was returned from bpf_sk_lookup_xxx\ (). * Return * 0 on success, or a negative error in case of failure. + * + * int bpf_msg_push_data(struct sk_buff *skb, u32 start, u32 len, u64 flags) + * Description + * For socket policies, insert *len* bytes into msg at offset + * *start*. + * + * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a + * *msg* it may want to insert metadata or options into the msg. + * This can later be read and used by any of the lower layer BPF + * hooks. + * + * This helper may fail if under memory pressure (a malloc + * fails) in these cases BPF programs will get an appropriate + * error and BPF programs will need to handle them. + * + * Return + * 0 on success, or a negative error in case of failure. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -2303,7 +2320,8 @@ struct bpf_stack_build_id { FN(skb_ancestor_cgroup_id), \ FN(sk_lookup_tcp), \ FN(sk_lookup_udp), \ - FN(sk_release), + FN(sk_release), \ + FN(msg_push_data), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index fda8c16..4e33511 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -104,6 +104,8 @@ static int (*bpf_msg_cork_bytes)(void *ctx, int len) = (void *) BPF_FUNC_msg_cork_bytes; static int (*bpf_msg_pull_data)(void *ctx, int start, int end, int flags) = (void *) BPF_FUNC_msg_pull_data; +static int (*bpf_msg_push_data)(void *ctx, int start, int end, int flags) = + (void *) BPF_FUNC_msg_push_data; static int (*bpf_bind)(void *ctx, void *addr, int addr_len) = (void *) BPF_FUNC_bind; static int (*bpf_xdp_adjust_tail)(void *ctx, int offset) =